Discovery of 'mini-brains' could change
understanding of pain medication
4 April 2017
brains', modifying how much information is sent to
the central nervous system.
The five year study found that nerve cells within the
ganglia can exchange information between each
other with the help of a signalling molecule called
GABA, a process that previously believed to be
restricted to the central nervous system.
Ganglia. Credit: Nikita Gamper, University of Leeds
The human body's peripheral nervous system
could be capable of interpreting its environment
and modulating pain, neuroscientists have
established, after successfully studying how
rodents reacted to stimulation.
Until now, accepted scientific theory has held that
only the central nervous system - the brain and
spinal cord - could actually interpret and analyse
sensations like pain or heat.
The peripheral system that runs throughout the
body was seen to be a mainly wiring network,
relaying information to and from the central
nervous system by delivering messages to the
'control centre' (the brain), which then tells the
body how to react.
The findings are published today in the Journal of
Clinical Investigation and have potential future
implications for the development of new painkillers,
including drugs to target backache and arthritis
pain.
Pain relief drugs
Current pain relief drugs are targeted at the central
nervous system and often have side effects
including addiction and tolerance issues.
The new research opens up the possibility of a
route for developing non-addictive and non-drowsy
drugs, targeted at the peripheral nervous system.
Safe therapeutic dosage of these new drugs can
also be much higher, potentially resulting in higher
efficacy.
Whilst the study showed a rodent's peripheral
nervous system was able to interpret the type of
stimulation it was sensing, further research is still
needed to understand how sensations are
In recent years there has been some evidence of a interpreted and whether these results apply to
humans.
more complex role for the peripheral nervous
system, but this study by the Hebei Medical
University in China and the University of Leeds
highlights a crucial new role for the ganglia, a
collection of 'nodules'.
In addition, the theory would need to be adopted by
drug development companies and extensively
tested before laboratory and clinical trials of a drug
could be carried out. Should the findings be
adopted, a timescale of at least 15-20 years might
Previously these were believed to act only as an
energy source for messages being carried through be required to produce a working drug.
the nervous system. In addition, researchers now
Nerve arrangements
believe they also have the ability to act as 'mini
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Neuroscientist Professor Nikita Gamper, who led
therapeutic control of pain."
the research at both universities, said: "We found
the peripheral nervous system has the ability to
Research Council support
alter the information sent to the brain, rather than
blindly passing everything on to the central nervous Dr Kathryn Adcock, Head of Neurosciences and
system.
Mental Health at the Medical Research Council,
which part funded the work, said: "These findings
"We don't yet know how the system works, but the are an interesting step in advancing scientists'
machinery is definitely in place to allow the
understanding of the mechanisms underpinning
peripheral system to interpret and modify the tactile pain perception. We are committed to supporting
information perceived by the brain in terms of
work such as this to aid the continued search for
interpreting pain, warmth or the solidity of objects. new and better pain treatments."
"Further research is needed to understand exactly
how it operates, but we have no reason to believe
that the same nerve arrangements would not exist
in humans.
A view from industry
Lishuang Cao, head of Membrane Physiology at
GlaxoSmithKline R&D in Shanghai commented on
this research: "This interesting finding could pave
"When our research team looked more closely at
the way for developing novel pain medicines by
the peripheral system, we found the machinery for targeting the peripheral GABA signaling pathway
neuronal communication did exist in the peripheral and at the same time avoiding or reducing the side
nervous system's structure. It is as if each sensory effects of many existing pain killers.
nerve has its own 'mini-brain', which to an extent,
can interpret incoming information."
"Further work is needed to understand the
physiological role of GABA in painful situations like
Co-author of the study, Professor Xiaona Du from inflammatory, neuropathic and chronic pain. More
Hebei Medical University, added: "This dramatically importantly we need to know if the same
changes our understanding of pain medication
mechanism is present in human beings' peripheral
because in theory it is now possible to target drugs nervous systems."
at the peripheral nervous system which could widen
the type of treatments available."
More information: Xiaona Du et al, Local
GABAergic signaling within sensory ganglia
Professor Gamper believes the findings may
controls peripheral nociceptive transmission,
present a challenge to the accepted 'Gate Control Journal of Clinical Investigation (2017). DOI:
Theory of Pain'. The theory holds that a primary
10.1172/JCI86812
'gate' exists between the peripheral and central
nervous systems, controlling what information is
sent to the central system.
Provided by University of Leeds
The study now suggests the transmission of
information to the central nervous system must go
through another set of gates, or more accurately a
process similar to a volume control, where the flow
of information can be controlled by the peripheral
nervous system.
"Peripheral nerves have the ability to dial up or
down the signal which goes through these gates to
the brain", said Professor Gamper. "Importantly, we
believe that these gates can be exploited for
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APA citation: Discovery of 'mini-brains' could change understanding of pain medication (2017, April 4)
retrieved 7 May 2017 from https://medicalxpress.com/news/2017-04-discovery-mini-brains-painmedication.html
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